Dark-room lantern.



R. JOHN.

DARK ROOM LANTERN.

APPLlOATION HLED APR.26, 1915.

Patented Jan. 16,

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ST AVAILABLE coe- UNITED STATES PATENT OFFICE.

ROBERT JOHN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE,ASSIGNMENTS, TO ICONO- CHROME COMPANY OF AMERICA, INC., A CORPORATION OF NEW YORK.

I DARK-ROOM LANTERN.

either a colored light composed of such actinic rays as have slight action upon a colorsensitive photographic plate, whereby the plate may be developed without danger of fogging, or a strong white light when the same is necessary for reexposing a plate during such processes as require a reversal of the image or the redevelopment of a positive.

ff Another object of the invention is to provide a combination dark-room lantern of this character, in which the eyes of the. operator will at all times be shielded from the glare of the light through the illuminated panes or screens.

i The details of the invention will hereinafter fappear and the novel features thereof will -be pointed out in the claims.

In the accompanying drawings; Figure l is a front elevation of a dark-room lantern constructed in accordance with the principles of my invention, and Fig. 2 is a transverse section, taken on' the line 2-2 of Fig. 1, and looking in the direction of the arrows.

In the construction shown, the lantern comprises an oblong box or casing 1, preferably made of sheet metal, although wood or any other desired material may be used. This casing has two windows in its front face which are closed by the panes 2 and 3, and through .which the rays from a source of white light within the casing are adapted to shine. The pane 2, is preferably of frosted glass or other suitable material which diffuses the white light as it passes therethrough. The same is vertically disposed and is surrounded by a suitable metallic frame l by means of which the pane is inset a short distance behind the front wall of the casing, to which the inwardly extending flanges 5 of the frame are secured,

Specification of Letters Patent. Patented J an, 16, 1917. Application filed April 26, 1915. Serial No. 24,033.

providing a recess or chamber 5. Hinged at the top of the frame 4:, as at 6, is a cover conslsting of an outer plate 7 and a panshaped plate 8, which has its edges resting against the plate 7 to provide flanges 9. The

pan-shaped part 8 of the cover is of a suit able size to fit snugly within the recess 5 formed by the frame 4, so that the cover is light-tight when closed.

The pane 2 is of substantially the same length as the casing l, but is of slightly less height, leaving a space between the frame t and the top wall of the casing 1, which is closed by the pane 3. The pane 3 is also pref-' erably held in a suitable metallic frame 9 and is positioned to the front of the vertical pane 2 and at an angle thereto. The end and top Walls of the casing 1 are extended forwardly and are joined to the frame 9, which is so mounted as to make a lighttight joint between it and the top of the frame 4. The rays of white light from the source within the casing are thus prevented from passing to the exterior of the casing except through the pane 3, when the cover for the pane 2 is closed.

It is through the pane 3 that the light passes for illuminating the plate during development. The same is therefore made of a suitably colored translucent material to screen out the rays of light to which the photographic plate is sensitive. For example, if the lantern is designed for use with a well known plate for color photography which is sensitive to the actinic rays of the spectrum having wave lengths less than 650 micro-millimeters, (which rays occur in the red portion of the spectrum), two pieces of glass coated with gelatin and suitably dyed to provide a ray filter which will permit only.

those rays to pass therethrough which are of a' greater Wave length than 670 micro-millimeters, are employed. The emulsion on one BEST AVAILABLE coP wardly through the pane 3 to illuminate an area below or on a level with the lantern. The developing dish containing the sensitive plate is of course positioned within this 5 area. When the casing 1 is of sheet metal the polished surface thereof acts aS a refleeting surface, but when othenmaterials are used, such as wood, the inner walls are made reflecting surfaces by painting them white, or separate reflectors may be used.

Since the top wall of the casing 1 extends over the pane 3, that portion of this wall directly above said pane serves as a shield or screen to protect the eyes of the person developing the plate from the glare of light passing through the illuminated pane 3, while at the same time permitting him to clearly see the plate during development since the light is directed upon the limited 0 area in which the plate is positioned. This arrangement has been found to be very satisfactory, as it enables theoperator to watch closely the process of development with little strain upon the eyes.

When a sheet metal casing is used, it is desirable to provide means for ventilating the same in order to prevent it from becoming unduly heated. An outer casing 13 has been shown which surrounds the casing 1 with the exception of its front face; it is joined to the walls of the inner casing 1 by flanges 14. Ventilating openings 15 are provided in one of the end-walls of the inner casing 1 through which the heated air may circulate and pass upwardly into the space between th two casings 1 and 18 and into the surrounding atmosphere through open ings 16 in the top wall of the outer casing.

If desired a ventilating opening 17 may be wprovided in the bottom wall of the outer casing in order to increase the'circulation of air between the walls of the two casings and to prevent the outer casing 1 from becoming unduly heated.

Two circular openings of substantially the same size are formed in the walls of the casings l and 13 at one end. Secured to and projecting from the casing 13 and surrounding the opening therein is a, threaded sleeve 18, and located within said openings and extending from the inner casing is a ring 19 which closes the space between the two casings. A threaded cap 20 carrying a lamp socket 21 and switch 22 fits over the thread- 'ed sleeve 18. The socket 21 carries an electric incandescent lamp 23 which, when the 7 cap is secured in place, is suitably positioned within the interior of the casing 1.

The cover for the pane 2 is moved to its open position by means of the springs 24 surrounding the pintle 25 of the hinge 6. These springs bear against the side flange 9 of the cover so that when the latter is free to move, they will carry it to the position 05 shown in full lines in Fig. 2, in which position the rays emanating from the lamp 23 pass through the pane 2 and flood the developing dish. The inner surface of the plate 8 then acts to reflect the light upon the developing dish, and also serves as a shield or screen to protect the eyes of the person using the lantern from the glare of the light. The cover is maintained in its light-tight closed position by means of a spring catch 26 secured to the bottom wall of the outer casing.

The lantern is preferably supported on short legs 27 which permit the air to enter through the ventilating opening 17.

I claim: 1

1. A dark room lantern comprising a casing adapted to contain an illuminant having two windows in its front face through which the rays from said illuminant are adapted'to pass, a ray filter in the upper of said windows, and an outwardly swinging light-tight cover for the other of said win dows pivoted along its upper horizontal edge.

2. A combination dark room lantern com prising a casing adapted to contain a1 illuminant, said casing having two window in its front face one of said windows being vertically disposed and having an outwardlj swinging light-tight cover therefor, th other of said windows being disposed abo'v said last named window and having a ra filter mounted therein extending forwardl of and .at an angle to said first name window.

3. A combination dark room lantern con prising a casing containing an illuminar said casing having an interior light refiec ing surface and two windowsin its fro] face, a ray filter in one of said windows, a1 a movable light-tight cover for the 0th of said windows, the illuminant and r: filter being-so positioned that the trar mitted light fromthe illuminant does 11 pass through the ray filter but the reflect light passes downwardly through the san 4. A combination dark room lantern co: prising a casing containing an illumina: said casing having an interior reflecting SI face and two windows in its front face movable light-tight cover for one of s: windows and 'a ray filter in the other of s: windows, the ray filter being disposed abc and extending forwardly from, said 5 named window at an angle thereto. and illuminant and ray filter being so positioi that the transmitted light from the illu nant does not pass through the ray fi but the reflected light passes downwar through the same.

5. A combination dark room lantern cprising a casing containing an illumin said casing having an interior reflecting face and two windows in its front face outwardly-swinging light-tight cover thereto, and the illuminant. and ray filter being so positioned that the transmitted light from the illuminant does not pass through the ray filter but the reflected lightfpasses downwardly through the same.

6. A combination dark room. lantern comprising a casing containing an illuminant,

said casing having an interior reflecting a surface and two windows in its front face,

a movable light-tight cover for one of said windows, a ray filter in the other of said nature, in the presence windows, the ray filter being disposed above, and extending forwardly from, said first named window at an angle thereto, the

illuminant and ray filter being so positioned that the transmitted light from the illumi- 2o nant does not pass through the ray filter but the reflected light passes downwardly through the same, and a shield over said ray filter.

In witness whereof, I subscribe my sig- :5

of two witnesses; ROBERT JOHN.

Witnesses:

WALDO M. GHAPIN,

JULE ZELENKO. 

